The proposed research is an evaluation of the reliability and validity of three types of laboratory measures of empathy in children at different ages and of different gender. Empathy is defined as an emotional response of an observer to the affect of another person where the observer's response is similar to that of the other person. The three classes of laboratory measures to be evaluated are: a) self-reports of emotion; b) analyses of facial expressions of affect; and c) physiological indices of autonomic arousal. Three experiments have been proposed. The first will be an assessment of the intercorrelations among the laboratory measures of empathy in children and will involve preliminary assessment of the relation between levels of empathy and social behavior in peer interactions. The second study is designed to permit comparisons of the effectiveness of different procedures for eliciting empathy in children in the laboratory and will explore further the relation between empathy and social behavior. The third study was designed to evaluate the validity and reliability of empathy measures for assessing empathy deficits in children with social behavior problems and pathological peer relations. The treatment of these issues will be focused on four specific aims: a) to establish reliable and valid procedures for the assessment of empathy in children for future research and clinical assessment; b) to provide empirical data for the evaluation and interpretation of findings from earlier research of empathy in children; c) to establish age and sex norms for empathy in children; and d) to provide empirical data for further development of theories of empathy in children.